Why on earth wouldn't it be drumphy's mess primarily with his poor handling of the 'rona?
It's just part of the picture. Sure, his handling of things made a mess here when it comes to workers and who could and couldn't work when things were "shut down".
That is the US part of the picture, many, many other countries shut down production, or companies did because of demand, safety, etc.
Wood is a great example. They slowed production due to lack of demand, but then demand went nuts and wood couldn't keep up. They were playing catch up and probably still are. That's one of many industries. Chip makers can't make chips quick enough, and the demand for those is only going up.
We all didn't realize how good our supply chain actually was, but now we know since it's having trouble keeping up.
Plus a lot of workers are literally no longer alive, so there is a smaller work force to produce everything. Then you have the fact that those same workers who were out of work during the shut down found new jobs that made it possible for them to not return to their production level job.
The entire things is massively convoluted, which is why when one tiny thing happens, the cascade is difficult to stop.
It also doesn't help that companies see the word inflation and realize they can just raise their prices and say "but inflation"...